[49.09] The W3~IRS5 Cluster: Radio Continuum and Water Maser Observations

High-sensitivity and angular resolution observations of the radio continuum
toward W3~IRS~5, along with observations of strong water masers have been made
with the VLA. At least seven distinct radio continuum sources have been
discovered, which are most likely a cluster of B0.5 - B0 stars with
ionized stellar winds. This is
in contrast to previous interpretations of observational data, which suggested
that IRS~5 is a single massive protostar with bolometric luminosity of $2\times
10^5$ L\sun. The spatial distribution of the water masers roughly follows
that of the radio sources; and these masers show a gradient in radial velocity
similar to that found in a larger-scale molecular outflow. We suggest that
previously observed, multi-component absorption in CO infrared transitions
traces outflows from the several stellar wind sources, rather than episodic
outbursts from a single source.